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Enzyme
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Target Concepts:
Gene/Protein
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Query: UNIPROT:P00750 (
PLA
)
16,800
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Poly(lactic acid),
PLA
, was blended with monomeric and oligomeric plasticizers in order to enhance its flexibility and thereby overcome its inherent problem of brittleness. Differential scanning calorimetry, dynamic mechanical analysis, transmission electron microscopy, and tensile testing were used to investigate the properties of the blends. Monomeric plasticizers, such as tributyl citrate, TbC, and diethyl bishydroxymethyl malonate,
DBM
, drastically decreased the T(g) of
PLA
, but the blends showed no morphological stability over time since rapid cold crystallization caused a size reduction of the amorphous domains in
PLA
. Consequently, the ability of
PLA
to accommodate the plasticizer diminished with the increase in crystallinity and migration of the plasticizer occurred. Increasing the molecular weight of the plasticizers by synthesizing oligoesters and oligoesteramides resulted in blends that displayed T(g) depressions slightly smaller than with the monomeric plasticizers. The compatibility with
PLA
was dependent on the molecular weight of the oligomers and on the presence or not of polar amide groups that were able to positively interact with the
PLA
chains. Aging the materials at ambient temperature revealed that the enhanced flexibility as well as the morphological stability of the films plasticized with the oligomers could be maintained as a result of the higher molecular weight and the polar interactions with
PLA
.
...
PMID:Preparation and properties of plasticized poly(lactic acid) films. 1587 6
In this work, rare earth europium was combined with different organic ligands to obtain two kinds of rare earth conversion agents, Eu(
DBM
)
4
CPC and Eu(TTA)
3
(TPPO)
2
. Two kinds of conversion films were successfully prepared by combining them with polylactide and poly(butylene adipate-co-terephthalate). Results showed that the film has excellent light conversion ability and high color purity, and rare earth complexes improved melt flowing property and decreased melt viscosity of blend. At the same time, the elongation at break of the film increased greatly, which could up to 595.0/460.9% in the both machine direction (MD) and transverse direction (TD). The results of GPC show that rare earth complexes can make main chain of
PLA
scission, which causes rapid molecular weight reduction, and the effect of Eu(
DBM
)
4
CPC on the molecular weight of
PLA
was more significant than Eu(TTA)
3
(TPPO)
2
. SEM shows that the complicity of
PLA
and PBAT has been improved, the dispersed phase of the blend is more uniform. DSC shows that both rare earth complexes can improve the crystallization capacity of
PLA
. And with the addition of cetylpyridinium chloride could improve the compatibility of rare earth complexes and polymer materials, the light transmittance and hydrophilicity of the film also increased obviously.
...
PMID:Exploring polylactide/poly(butylene adipate-co-terephthalate)/rare earth complexes biodegradable light conversion agricultural films. 3064 Nov 91
